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    <title>Document</title>
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    <script type="text/javascript">
        function Foo(b){
            this.a=b;
        }
        var obj1={};
        var bar = Foo.bind(obj1);
        bar(2);
        console.log(obj1.a);//2
        var baz = new bar (3);
        console.log(obj1.a);//2
        console.log(baz.a);//3
    </script>
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